Multilingual text alignment consists in putting face to face two texts in different languages. By text, we mean here any equivalent unity like a paragraph, a sentence, an expression or a word. This technique is used for automatic translation and gives its best results when the corpus is wide (to cover the maximum number of use cases, as it is a statistical approach) and the vocabulary reduced.
Beyond this automatic use, the site Linguee proposes both an editorial dictionary and a search engine.
When you enter a word or an expression in their search egine, the result shows face to face the possible expression in the source language and its translation in the target language, as well as examples from other sources, i.e. multilingual websites they parsed to show the expressions used in context to cover as many use cases as possible.
I let you imagine the usefullness of that tool for very specialized or not yet widespread expressions when you are using your day-to-day translation helping tools.
The visitors can vote for a translation with one click if they consider the proposed example in the target language a good one, helping this tool getting better in a crowdsourced way.
The actually supported couples of languages are English/French, English/German, English/Portuguese and English/Spanish.
Alineación de texto plurilingüe con Linguee (in Spanish)
Alignement de texte multilingue avec Linguee (in French)
Alinhamento de texto multilíngue com Linguee (in Portuguese)